One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,6,5)(3,8,4,7)(9,10,13,12)(11,15,16,14)(20,24)(22,23)(25,26)(27,33)(28,36)(29,30)(31,35)(32,37)(34,38)(39,40)(1,3,6,4)(2,7,5,8)(9,10)(11,15)(12,13)(14,16)(17,18,21,19)(20,22,24,23)(26,29)(31,33)(32,36)(38,39)(3,4)(7,8)(9,11)(10,14)(12,15)(13,16)(17,19,21,18)(20,23,24,22)(25,27,30,35)(26,31,29,33)(28,34,37,40)(32,38,36,39)(1,4,6,3)(2,7,5,8)(9,11)(10,15)(12,14)(13,16)(17,20)(18,22)(19,23)(21,24)(25,28,30,37)(26,32,29,36)(27,34,35,40)(31,38,33,39)(1,5,6,2)(3,8,4,7)(9,12,13,10)(11,15,16,14)(25,29,30,26)(27,33,35,31)(28,32,37,36)(34,38,40,39)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.